Derrick structure



, May 6, 1941. c. J. Mm

DERRIGK STRCTURE 2 Sheeibs-Sheet l Filed Jap. zo. 1946 uw @l um l' @C un IN V EN TOR. C. .l MOON A TTORNEY S.

May 5, 1941- c. J. MooN .DERRICK STRUCTURE 'Filed Jan. 2o. 1940 v2 Sheets-Sheet 2 FIG. 7

N l N lll/1.4 r." A

MVP

INVENTOR. MOON A TTORNEYS.

- Patented May 6,.- 1941 Cleon James Moon,

Tulsa, Franks Manufacturing Corporation,

Okla., assignor to Tulsa,

Okla., a corporation of Oklahoma Application January 20, 19,40, Serial No. 314,801

(ci. iss-i) 2 Claims.

This invention relates to an improved derrick adapted particularly for use with portable drilling rigs wherein it is especially desirable to employ a form of derrick which can be quickly and easily raised or lowered for'use or transportation, respectively, as required.

A principal object of this invention is to provide an improved form of base structure for derricks which are adapted to be transported bodily or in sections from place to place, and which are to be assembled on the ground into a complete structure and then raised bodily into place for use.

i Another object resides in the provision ci a novel form of footing for the derrick structure which cooperates with a novel base member whereby the raising and lowering of the complete derrick is greatly facilitated.

A more specific object is the provision of a novel form of derrick footing which cooperates with a complementary base member so that the -vertical center of gravity of the complete derrick structure is always forward of the base hinge point about which it is raised and lowered.

Still another object is the provision of a derrick base structure wherein the legs of the derrick are provided withl arcuate footings which cooperate with complementary bearings on a base member whereby the entire derrick structure may be assembled apart from the base member and then raised bodily thereon by rotational engagement of the footings with the base bearings.

Other and more specific objects and advantages of this invention will be understood from the following detailed description, when read in conjunction with the accompanying drawings which illustrate one modification of this invention'.

In the drawings: I l

Fig. 1 illustrates a general assembly in vertical position and ready for use of a well drilling derrick having a base structure in accordance with the invention. l

Fig. 2 is an enlarged view of the base portion of the derrick in the assembly illustrated in Fig. 1.

Figs, 3, 4 and 5 are more or less diagrammatic views showing three-different positions of the cooperating derrick iootings and base members forming the subject of this invention.

Fig. 6 is an enlarged d etail showing one side of the base member.

Figs. 7 and 8 are longitudinal sections taken along lines 1-'I and 8 8, respectively of Fig. 6.

' wardly.

Fig. 91s an enlarged detail showing one side of the derrick footing o1' this invention, and

Fig. 10 is a longitudinal section taken along line l-I of Fig. 9.

Referring to the drawings and to Figs. 1 and 2 in particular, a derrick I is shown mounted in vertical operating position on one end of a base frame 2, on the opposite end of which is mounted the usual rig power plant 3. 'Ihe usual draw works 4 is shown positioned on the frame 2 just at the rear of the derrick and includes the ordinary winch drum 5 about which the commonly used drilling and hoisting lines are conventionally wrapped. Extending rearwardly from the derrick over the base frame 2 is a boom 6. A derrick hoisting line 1 which is wrapped about winch drum 5, is threaded through a pulley 8, which is anchored to the forward end of frame 2, and is connected to the free end of boom B and extends thence through a pulley sheave I0 positioned at the crown of the derrick and back to winch drum 5. By suitable rotation of winch drum 5, the derrick may be raised and lowered relative to the frame through the medium of hoisting line 1 and the cooperation of boom B. The structure and method employed for raising and lowering a tower or derrick structures are more or less conventional and well understood generally and need not be elaborated upon in any greater detail herein, since they form no essential part of the present invention.

Thevderrick structure I is of the usual pyramid form, only one side of which is shown, having a front leg 9 and a rear leg III, rigidly connected together by the usual cross bracing members II. Only one side of the derrick is shown in each of the drawings since the other side is identical and it will be understood, therefore, that the detailed description of the side shown will be applicable to the other side of the derrick not appearing in the drawings. Rear leg I0 is somewhat shorter than front leg 9 and is adapted to rest upon a pillar I2 extending upwardly from base frame 2 when the derrick is in the raised position. Front leg 9 is provided with an arcuate shoe I3 which is rigidly attached near the lower end thereof and faces down- The shoe has substantial width so that its lower base provides an adequate `hearing surface. A second arcuate shoe Il of generally similar construction is positioned rearwardly of shoe I3 and is rigidly attached thereto by a horizontal brace I5. An` angle brace I6 extends upwardly and forwardly from the top of shoe I4 and is rigidly attached to front leg 9 at a point above have their centers on the same horizontal line.

The legs and bracing members of the derrick are preferably tubular in construction for maximum load carrying capacity, but may be made of metal structural members of other convenient and well known shapes. The lower end'of front leg 9 is provided with an internally threaded collar I8 (Fig. l) into which is threaded an extensible footing member I/B which is employed to provide additional support for this leg -as will appear later.

Base frame 2 consists of a pair of spaced parallel `members 2a, which are preferably H-beams, but may be channels or I beams or other suitable and well known shapes. These side members 2a are suitably cross braced for rigidity. Only one of the side members 2a appears in the drawings lbutsince the other side is identical in appearance and construction, the following description isequally applicable thereto. On the side member 2a of the forwardportion of base frame 2, upon which the derrick I is :to be carried, are mounted longitudinally spaced front and rear bearings 20 and 2|, respectively. Bearings 20 and 2| are of circular shape and of substantial width and are adapted to receive shoes I3 and I4, respectively, for rotation thereon. Bearings 20 and 2| have equal radii and are insertable within the arcs of shoes I3 and I4. Front bearing 20 -has its center at a lower horizontal level, considering the derrick in rits vertical position, than rear bearing v2|. Thus, a. line connecting the centers of the bearings would form an angle with the horizontal. This angle is preferably about 8 degrees for a derrick of the type described herein, but may, of course, be greater or lesser, as desired, depending generally upon the dimensions of the derrick.

Each of the bearings 2|! and 2I-is provided about its horizontal edges with an upstanding outer flange 22 and a parallel inner flange 23. These flanges serve as guides ,to guide the rotation of shoes I3 and Il on the bearings and to prevent lateral displacement of the shoes from the bearings.

The described derrick base structure functions in the following manner in raising and lowering the derrick: The derrick I is first completely assembled on the ground in the horizontal position, as indicated in dotted outlines in Fig. 2. While in horizontal position the derrick is moved toward the forward end of -base frame 2 so that shoe I3 is outside of frame member 2a and is engaged on bearing 20 between flanges 22 and 23. It will be understood, of course, that the corresponding front shoe on the opposite side of the derrick is simultaneously brought into engagement with the corresponding front bearings. A hoisting force is then applied to the upper end of the derrick through the medium of hoisting line 'I and the cooperation of boom 6 and pulley 8, by power applied to winch drum 5, and the entire derrick is then raised toward the vertical position, shoe I3 rotating about bearing 20 which forms the hinge point forv theinitial portion of the raising operation. The positions of the derrick footing and shoe I3 with, relation to the base frame and bear-y ing 20 as the raising operation is begunis shown in Fig. 3. Obviously, at this point the center of gravity of the derrick is far forward of the hinge point formed by bearing 20. Raising of the der- -rick is continued until rear shoe I4 comes into contact with rear bearing 2|. This position is shown in Fig. 4. Since rear bearing 2| is at a' higher level than front bearing 20, the derrick will still be tilted forwardly and its center of gravity will still 'be forward of the hinge point. which, at this point in the operation, is still bearing 2li. Now, the raising of .the derrick is continued, but in doing so, the hinge point is automatically shifted rto rear bearing 2|, and while the center of gravity of the derrick also shifts rearwardly to some Ipoint between bearings 20 and 2|, it will still be forward of the new hinge point, and the weight of the derrick will still be opposed to the raising force. As the derrick rotates toward its nal vertical position about bearing 2|, shoe I3 will be lifted out of contact with bearing 20 and the full weight of the derrick will lbe supported on bearing 2|. The raising is continued until 'a position is reached at which the centers of shoes I3 and Il are at substantially the same level which will ordinarily coincide with the horizontal. At this point rear leg I0 will have come to rest on pillar I2 and no further rearward rotation of 'the derrick about bearing 2| can occur. Extensible footing I 3 is then extended until it comes to rest on the ground or on some suitable support and front leg 9 will now be fully supported, the load thereon being distributed between .rear bearing 2| and footing I9.

By the described cooperation of shoes I3 and I4 with bearings 20 and 2|, it will be eviden-t that itwill be unnecessary to snub the derrick during the/raising operation, against toppling.

over rearwardly. For by shifting the hinge point as described, the center of gravity of the derrick is always forward of the hinge point during the entire raising operation and until the rear legs of the derrick come to rest upon their supporting pillars, and the weight of the derrick is, therefore, always opposed to .the hoisting force. This arrangement, therefore, reduces the rigging operations ordinarily required in raising such tall and heavy structures reduces the supervision required and greatly facilitates the raising of the derrick toits operating position.

When the derrick is lowered, footing I9 is retracted to remove the support from under the lower end of front leg 9, and it becomes only necessary to slacken hoisting line 1 to permit the derrick to start to fall forwardly, rotating about bearing 2 I. The hinge point then shifts to bearing 20 when shoe I3 comes in contact therewith and the remainder of the descent of the derrick is accomplished by rotation about bearing 20 as fthe hinge point. Since the center of gravity of the .derrick is always forward of the hinge point, whens'the support of footing I9 is removed from front leg '9, the derrick starts down of its own weight, and continues all the way down of its own weight being held -back only by tension on hoisting line 'I. This arrangement eliminates the need for .the eXtra power ordinarily needed tostart the derrick toppling, that is, to move the center of gravity forwardly of the hinge .point about which it is lowered. Thus only a minimum amount of power is needed for the lowering and raising operations in addition to the other advantages previously referred to. When the derrick has iinally been lowered to the ground it is only necessary to pull or slide the derrick horizontally forward from the end of base frame 2 to separate the derrick from the base frame. The base frame with its power plant can then be loaded on a transport vehicle, and the derrick disassembled in a minimum number of umts and also loaded on a suitable transport vehicle. The entire drilling rig can .thus -be quickly and easily transported to a new location and quickly set up for additional drilling operations.

It will be evident that each of the bearing members 20 and 2| with its corresponding bearing member on the opposite side of the base forms a pivotal axis for the derrick which extends transversely across the base. 'Ihus a pair of spaced parallel pivotal axes are provided, the rear one formed by bearings 2l being elevated relative to that formed by bearings 20, and that the axis of rotation of the derrick shifts successively from one to the other during its rotation on the base.

tudinally spaced from each other, the rear ones of said bearing members being positioned at a higher level than the corresponding forward bearing members, a pair of arcuate shaped shoes attached to the lower end of each of said front legs of said derrick, one of the shoes of each pair being fixedly positioned rearwardly of the other and having its center of radius on the same level as the other one of said shoes when the derrick is in fully erected position, each of said pairs of shoes cooperating with the adjacent pair of said bearing members to provide a rearwardly shifting axis of rotation for said derrick as it is raised from the horizontal to the vertical position, means to support the rear legs of the derrick when said derrick is in the vertical operative position and means for raising and lowering the derrick between horizontal and vertical positions.

2. The combination of a derrick, including a base portion and a superstructure, having a pair of spaced legs on opposite sides of the base portion at the front thereof and a pair of legs at and in this way the vertical center of gravity oi' the derrick is maintained always in advance of its axis of rotation.

It will be understood that the derrick base structure of this invention can be employed with two-legged A-frame derricks or other derrick forms in similar manner and with equal advantage as it is employed with the four-legged pyramid derrick described herein by way of illustration.

Various alterations and modications may be made in the size, form and details andln the arrangement oi' the parts of this invention without departing from the scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. In combination with a derrick having a pair of spaced front legs and a pair of rear legs, a base structure upon which said derrick is rotatively mounted for raising and lowering between horlzontal and vertical positions, comprising, a frame having spaced parallel side members spannedby said derrick, a pair of arcuate bearing members mounted on each, of said side members and longithe rear of the derrick on opposite sides of said base portion, a base member upon which said derrick is rotatably mounted for raising and lowering between horizontal and vertical positions, pairs of parallel longitudinally spaced arcuate bearing members mounted on opposite sides of said base member, the rear bearing member of each pair being positioned at a higher level than the corresponding forward member, an arcuate shaped footing attached to each of the front legs of the derrick, one of the footing's of each pair having its center of radius on the same level when the derrick is in fully erected position, each pair of footings cooperating with the adjacent pair of bearing members to provide a double axis of rotation for said derrick about the base, the axis of rotation shifting from the front bearing members to the rear bearing members as the derrick is raised and in the opposite direction as the derrick is lowered, means to supportthe rear legs of the derrick when said derrick is in the vertical operative position and means for raising and lowering the derrick between horizontal and vertical positions.v

CLEON JAMES MOON. 

